RabbitMQ River

Another River implementation, RabbitMQ River allowing to automatically index a rabbitmq queue. The format of the messages follows the new bulk api format:

{"index":{"_index":"twitter","_type":"tweet","_id":"1"}{"tweet":{"text":"this is a tweet"}}{"delete":{"_index":"twitter","_type":"tweet","_id":"2"}}{"create":{"_index":"twitter","_type":"tweet","_id":"1"}{"tweet":{"text":"another tweet"}}